Remove to_vec from day2

More refactoring soon.

src/day2.rs

@@ -1,6 +1,6 @@
 use std;
 
-fn compute_intcode(p: &mut Vec<usize>) -> Vec<usize> {
+fn compute_intcode(p: &mut Vec<usize>) {
     for idx in (0..(p.len())).step_by(4) {
         match p[idx] {
             1 => {
@@ -16,10 +16,9 @@ fn compute_intcode(p: &mut Vec<usize>) -> Vec<usize> {
                 p[res] = p[left] * p[right];
             }
             99 => break,
-            _ => panic!("Something went wrong!"),
+            _ => panic!("invalid opcode"),
         }
     }
-    p.to_vec()
 }
 
 pub fn part_one() {
@@ -32,7 +31,9 @@ pub fn part_one() {
     input[1] = 12;
     input[2] = 2;
 
-    println!("Intcode [0] is: {}", compute_intcode(&mut input)[0]);
+    compute_intcode(&mut input);
+
+    println!("Intcode [0] is: {}", input[0]);
 }
 
 pub fn part_two() {
@@ -52,8 +53,8 @@ pub fn part_two() {
         input[1] = i;
         for j in 0..99 {
             input[2] = j;
-            let mut input_guess = input.clone();
-            let computed = compute_intcode(&mut input_guess);
+            let mut computed = input.clone();
+            compute_intcode(&mut computed);
 
             found = computed[0] == lookup_num;
 
@@ -76,20 +77,19 @@ pub fn part_two() {
 
 #[test]
 fn test_part_one() {
-    assert_eq!(
-        compute_intcode(&mut vec!(1, 0, 0, 0, 99)),
-        vec!(2, 0, 0, 0, 99)
-    );
-    assert_eq!(
-        compute_intcode(&mut vec!(2, 3, 0, 3, 99)),
-        vec!(2, 3, 0, 6, 99)
-    );
-    assert_eq!(
-        compute_intcode(&mut vec!(2, 4, 4, 5, 99, 0)),
-        vec!(2, 4, 4, 5, 99, 9801)
-    );
-    assert_eq!(
-        compute_intcode(&mut vec!(1, 1, 1, 4, 99, 5, 6, 0, 99)),
-        vec!(30, 1, 1, 4, 2, 5, 6, 0, 99)
-    );
+    let mut intcode = vec![1, 0, 0, 0, 99];
+    compute_intcode(&mut intcode);
+    assert_eq!(intcode, vec!(2, 0, 0, 0, 99));
+
+    let mut intcode = vec![2, 3, 0, 3, 99];
+    compute_intcode(&mut intcode);
+    assert_eq!(intcode, vec!(2, 3, 0, 6, 99));
+
+    let mut intcode = vec![2, 4, 4, 5, 99, 0];
+    compute_intcode(&mut intcode);
+    assert_eq!(intcode, vec!(2, 4, 4, 5, 99, 9801));
+
+    let mut intcode = vec![1, 1, 1, 4, 99, 5, 6, 0, 99];
+    compute_intcode(&mut intcode);
+    assert_eq!(intcode, vec!(30, 1, 1, 4, 2, 5, 6, 0, 99));
 }